Method of and apparatus for folding sheet material



Feb. 26, 1929. 1,703,456

F. M. POTTER METHOD OF AND APPARATUS FOR FOLDING SHEET MATERIAL OriginalFiled May 19, 1923 s Sheets- Sheet 1 Feia. 26, 1929. I 1,703,456

F. M. POTTER 7 METHOD OF AND APPARATUS FOR FOLDING SHEET MATERIAL YOriginal Filed May 19, 1923 3 Sheets-Sheet 2 vwemtoz Feb, 26, 1929.1,703,456

F. M. POTTER METHOD OF AND APPARATUS FOR FOLDING SHEET MATERIAL OriginalFi led May 19, 1923 3 Sheets-Sheet 3 the folding operation and inPatented Feb. 26, 1929.

UNITED STA FRANK M. POTTER, OF ROME, NEW YORK, ASSIGNOR TO GENERAL CABLECORPORA- TION, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY. I

MET HOD OF AND APPARATUS FOR FOLDING SHEET MATERIAL.

Application filed May 19, 1923. Serial No. 640,288. Renewed July 19,1928.

The present invention relates to improvements in the art of foldingfiatstock and ,comprehends improvements in the method of folding, inapparatus for performing the resulting structure. Among other objectsthe invention aims to provide a method and apparatus by which a strip offlat stock may be folded along longitudinal lines in indeterminatelengths and in the particular embodiment of the invention hereinillustrated another object of the invention is to produce a laminatedstructure in indeterminate lengths from a strip of flat stock of singlethickness. The particular embodiment. of the-juvention herein selectedfor illustratio'nfl. and description comprehends a method and up paratusby which a laminated .tape of fibrous material such as paper may beproduced from a strip of material of a single thickness, although itwill be apparent that atleast certain features of the invention areuseful in other connections. For the purposes of this description,reference will be made only to the specific embodiment of the inventionshown and to the product which that embodiment is particularly designedto produce.

Laminated paper tape such as that shown and described herein may findmany differentuses in widely diversified industries, in fact it will beuseful wherever a relatively -fiexible and strong tape is desirable. Itwill be particularly useful as a structural element in the protectiveand insulating covering of electrical conductors inasmuch as paperpossesses insulating properties and when properly treated and appliedprovides an excellent protective covering for the conductor. Inasmuch asthe present embodiment of the invention is primarily intended for use asan element in the covering material of electrical conductors it will bedescribed solely in that connection, although other uses for the tapewill at once be apparent.

A. preferred embodiment of the invention has been selectedfor'illustration and is shown in the accompanying drawings,

wherein Figure 1 isea side elevation of foldin apparatus particularlydesigned for con vert ng flat stock into a laminated tape,

Figure 2 is a cross-section thereof on the line 22 of Figure 1,

. Figures 3 to 7 inclusive are semi-diagrammatic views which illustratethe drawmg dies and the manner in which the folding of a strip of fiatpaper stock is accomplished; Figure 3 being a view of the drawmg diesfrom beneath; Figure 4 being a view of the tape from beneath showing.the successive folds; Figure '5 consisting oi a series of cross-sectionsof the tape as it progresses from flat stock at the right to the finalproduct at the left; Figure 6 being a view of the tape from aboveshowing the umor III llVlIlCllglt is folded; and lugure 4 being a viewof the drawing dies from above.

1*1gure 8 1s a diagrammatic elevation o the drawing dies looking fromthe rear of I igure 1 with the plate upon which the dies are mountedremoved.

Figures 9 to 15 inclusive are cross-sections on the lines 99, 1010, etc,of F ig Figures 16 is a perspective view of the drawing dies showing thepaper passing therethrough and looking from the back of the machineshown in Figure 1.

Referring to the drawings, the operating parts of a suitable apparatusembodying the invention are mounted upon a bed plate 20. A supply offlat stock, herein a strip of paper 21. is carried by a spindle 22ournaled between two supporting legs of the bed 20. This strip of paper21 is led over a guide roll 23 and through a series of drawing dies 24to 29 inclusive which are fixed in a plate 30 mounted upon a standard31fast to the bed of the machine. These drawing dies, which will laterbe described in detail, operate to fold the paper upon itself a suitablenumber of times and the paper so folded is led between rolls 32 and '33which not only act as feed rolls but also operate to firmly crease thetape and gauge the size thereof. The feed roll 33 is provided with aperipheral groove 34 which cooperates with a peripheral ridge 35 on theface of the feed roll 32. The feed roll 33 is fast to a shaft 36 whichis journaled in fixed hearings in similar standards 37 and carries agear 38 at its outer end. The feed roll 32 is fast to a shaft 39 whichis journaled in similar sliding blocks 40 so that the two shafts 36 and39 may be moved toward or away from each other. Means are provided forforcing the feed rolls into contact with the tape, herein shownassimilar screws 41 adapted to press downwardly upon the sliding blocks40. The shaft 39 carries a gear '42 at its outer end which meshes withgear 38 on shaft 36 so that the two feed rolls turn at the same speed inopposite directions and the diameters of the peripheral ridge 35 andgroove 34 are the,

standards 47 rising from the bed plate 20' and frictionally driven by abelt 48. which runs over a pulley 49 upon the shaft 39iand the pulley 50upon the shaft carrying the reel. I 1

The construction of the drawing dies will be clearly understood froman'examination of Figures 8 to 15 inclusive, it being unnecessaryto'describe each die in detail inasmuch as they resemble each other incertain respects. For example, the die 24' consists of two parts whichare both mounted in the plate 30. The lower part of this die'is cut awayat 61 so that in coo eration with the upper part 62 of the die it ormsan aperture of a length equal to the width of the tape and of a widthwhich will permit the tape to be easily drawn therethrough. This a andthe succeeding dies are herein shown as adapted to form a laminated tape"which is folded upon itself four times from one edge and once from theother edge, producing a finished product in which there are six laminae.Inasmuch as each successive folding of the paper requires a slightlygreater amount of stock to effect the fold, the second die 25 has itslower part 60 cut away to a less extent to form the aperture 61 of alength less than the aperture 611by a little less than one-fifth theoriginal width of the fiat stock. This second die 25 resembles the firstin that it has an upper part 62 but the cut away portion of the lowerpart 60 is different in that it is cut away for approximately one-fourthof its length to a depth slightly greater than two thicknesses of theoriginal stock forming a wider aperture at to position the first fold ofthe paper tape,

is clearly illustrated in Figures 10, 11, 12 and 16 and will be apparentwithout further description. The successive dies 26, 27, 28

and 29 are formed with apertures successively narrower than those of thedies 24 and 25 and the final die 29 has an aperture just long enough toaccommodate the finally I folded tape and wide enough topermit the sixthicknesses of the flat stock to be drawn therethrough.

Corresponding dies are correspondingly numbered with the exponent 1 forthe parts of die 25, ex-

ponent 2- for the parts of die 26 and'so on. As the flat strip is drawnthrough the dies it will be observed that the outer or lefthand edge inFigures 9 to 15 is repeatedly folded under. During this folding,assuming that the paper was being drawn in a successive dies along'theirregular lefthand edge of the tape inasmuch as the irregular edge thenapproximates a chord of the arc. By lessening the strain on this edge,the danger of tearing the tape wilhbe minimized.

Figures 3 to 7 inclusive illustrate very clearly the manner in which thetape is fold-.

ed and the relation of the successive dies to the folds in the tape.These figures are (diagrammatic to the extent that they do not showthe'dies arranged upon the are of a circle,otherwise they are entirelyin accordance with the other figures of the drawings. These figures arearranged so thatthe tape and dies are located in respect to each otheras they are located in the machi e, that is to say, the die 24 isapertured to pass the tape in the condition. shown along the verticalline between the two representations of that die in Figures 3 and 7. Thedie 25 accommodates the tape with one fold as shown directly therebelow.The same is true of the other dies shown in Figures 3 and 7. It

parts of the successive iso- 7 the die 29. Thereafter the tape passesbei and permits the tape to be wound'helically 'will be seen byreference to these I i strip first bends upwardly in Figure 4,

fi ures and gure 16 that the outer edge of the flat (downwardly inFigure 6') and is then drawn over or under as the case may be. andpressed flat against the undeformed "surface of the tape and creased inthe die 25. Similarly the doubled edge is again folded back upon thebody of the tape and pressed into contact therewith by the die 26. Allthese folds take place in the same direction until die 28 is reached.The shoe or guide 64 is so arranged with respect to the aperture in thedie 28 that the inner or unfolded edge of the tape will now be bent downover the edge of the said guide and the tape, folded into a structure ofsix thicknesses, will issuefrom tween the 'rolls 32 and 33 and is firmlypressed together.

uniform cross-section throughout, each layer being unattached except atits edge to any other layer and thereby permitting a slightrelativemovement or accommodation of the laminated tape to the. wire orcable which is being covered. 1 This avoids tears or wrinkles about theconductor with extreme accuracy so that the edges OfSllCCBSSlVB convolutons abut closely. Moreover this laminated construction is of advantageto increase the flexibility of the finished product inasmuch as, theseveral laminae permit. the tape to bend upon transverse-lines and thusthe tape will.

accommodate itself to any curvature which the electrical cable may takeduring installa' tion and use and without unduly opening up the seamsbetween adjacent convolutions. Furthermore, this form of tape results inan-economy in the. operation of covering electrical conductors in thatit may be.

wound thereon veryspeedily due to its ten- 'sile strength and to thefact that a plurality of'laye'rs ofpaper. are thus being applied to theconductor simultaneously.

It will be understood that the invention may be variously modified andembodied within the scope of the subjo'ined claims. I

I claim as my invention:

1. A method of folding strips of indeterminate length, which consists insucces-' sively folding a'single edge of the strip toward the oppositeedge, said successive fold= ing operations being performed about an'arcuate path, and finally subjecting said folded strip to a compressiveforce adapted to firmly crease the same. 2. A method of folding stripsof indeterminate length, which consists in drawing a strip through asuccession of dies ar- I ranged in an areuate path, and adapted toimpart successive folds to one edge of the strip, and then passing saidstrip through another die also arranged on said arcuate path and adaptedto impart a fold to said other edge.

3. A method of folding strips of indeterminate length, which consists indrawing a strip through a succession of dies arranged in an arcuate pathand adapted to impart successive folds to one edge of.the strip,

then passing said strip through another die also arranged on saidarcuate path and; adapted to im art a fold to said other edge, I

and finallysu jectin said folded strip to a compressive force a apted tofirmly crease the same. Y

4. In a machine for folding strips ofmaterial, in combination, means forfeeding a strip through said machine; a succession of (lies throughwhich said strip may-be fed; and means for holding said dies in anarmatepath.

5. In amachine for folding strips of material, in combination, means forfeeding a strip through said machine; a succession of diesthrough whichsaid strip may be fed; a

f 7. In a mac ine for folding strips of ma-..

terial, a plurality of dies arranged upon the arc of a circle and havingrelatively narrow apertures of progressively lessening width; and meansbetween said dies to determine the extent of successive folds.

' 8. In a machine for folding strips of material, in combination, meansfor feeding a strip through said machine; a succession of dies throughwhich said strip may be fed; means for holding said dies in an arcuatepath; and means whereby said feed means may also compress the foldedstrip.

- 9. In a machine for folding continuous strips, in combination, meansfor feeding a strip through said machine, a series of dies arranged inan arcuate pathand shaped to mpart successive folds to one edge of thestrip.

,10. In a machine for folding continuous :strips, in combination, meansfor feeding a strip through said machine. series of dies throu h whichsaid strip isjdra'wn successive- 1y, said'dies being arranged to impartsuccessive folds to one edge only of the strips said dies being arrangedin an arcuate ath and means for finally subjecting said fol s to acompressive force adaped 'to firmly crease the same. j p 11'. In amachine, for folding continuous strips, in combination, a series of diesarranged in an arcuate path adapted to impart successive folds to oneedge only of the strip, another die arranged to impart a fold to theother edge of the strip, and means for drawing the strip through theseveral dies.

12. In a machine for folding strips of material, a plurality of diesarranged upon they are of a circle and having relatively narrowapertures of progressively lessening] width 10 and means between saiddies over w ich an edge of the strip is folded .as itpasses from die todie. I

In testimony whereof, I have signed my name to this specification this18th day of 15 May, 1923.

FRANK. M. POTTER.

